* fs_dax_get_by_host in the hot path @ 2017-08-24 13:45 Christoph Hellwig 2017-08-24 14:48 ` Dan Williams 0 siblings, 1 reply; 3+ messages in thread From: Christoph Hellwig @ 2017-08-24 13:45 UTC (permalink / raw) To: Dan Williams; +Cc: linux-nvdimm, linux-fsdevel Hi Dan, I just noticed that we now do a fs_dax_get_by_host in every iomap_begin call for DAX. This function iterates a list, does a string compared and igrab. I really think we need to cache this in the superblock (possible even the fs superblock) similar to what we do for the block device. ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: fs_dax_get_by_host in the hot path 2017-08-24 13:45 fs_dax_get_by_host in the hot path Christoph Hellwig @ 2017-08-24 14:48 ` Dan Williams 2017-08-24 15:19 ` Christoph Hellwig 0 siblings, 1 reply; 3+ messages in thread From: Dan Williams @ 2017-08-24 14:48 UTC (permalink / raw) To: Christoph Hellwig; +Cc: linux-nvdimm@lists.01.org, linux-fsdevel On Thu, Aug 24, 2017 at 6:45 AM, Christoph Hellwig <hch@lst.de> wrote: > Hi Dan, > > I just noticed that we now do a fs_dax_get_by_host in every > iomap_begin call for DAX. This function iterates a list, > does a string compared and igrab. I really think we need > to cache this in the superblock (possible even the fs > superblock) similar to what we do for the block device. Sure, I'll get that fixed up. I believe I arrived at this scheme as a side-effect / misunderstanding of this comment: https://groups.google.com/d/msg/linux.kernel/9ho8SFe6RSw/6zTgNaNTCgAJ ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: fs_dax_get_by_host in the hot path 2017-08-24 14:48 ` Dan Williams @ 2017-08-24 15:19 ` Christoph Hellwig 0 siblings, 0 replies; 3+ messages in thread From: Christoph Hellwig @ 2017-08-24 15:19 UTC (permalink / raw) To: Dan Williams; +Cc: Christoph Hellwig, linux-nvdimm@lists.01.org, linux-fsdevel On Thu, Aug 24, 2017 at 07:48:18AM -0700, Dan Williams wrote: > Sure, I'll get that fixed up. I believe I arrived at this scheme as a > side-effect / misunderstanding of this comment: > > https://groups.google.com/d/msg/linux.kernel/9ho8SFe6RSw/6zTgNaNTCgAJ The current scheme is doing the right thing in terms of returning the dax device from ->iomap_begin. But it still do so efficiently :) ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2017-08-24 15:19 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2017-08-24 13:45 fs_dax_get_by_host in the hot path Christoph Hellwig 2017-08-24 14:48 ` Dan Williams 2017-08-24 15:19 ` Christoph Hellwig
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